At a residential construction site where a wooden house or the like is being built, normally, one or two construction workers are working. In such a small-scale construction site, a time recorder or the like could not be installed due to adverse conditions, such as lack of an installing space and power supply, so that any data necessary for managing working hours such as time-in and time-out recodes have been collected manually.
On the other hand, at a large scale construction site such as a construction site of a large building, there have been efforts for introducing work management software which employs a method such as CPM (Critical Pass Method) for optimizing the allocation of human and material resources etc. (for example, see JP-A-11-193631).
The work management software requires inputs of data indicating the allocation of human and material resources, and conventionally, those efforts to collect data and to input the collected data have been carried out manually.
Now, at a construction site, air compressors are installed in order to supply compressed air to pneumatic tools such as nailing machines, screwing machines and the like. Further, for anti theft purposes, there has been proposed an air compressor which requires an input of a given ID in order to be able to operate it (see JP-A-2004-116472, for example).
Furthermore, an air compressor capable of receiving an input of an ID code through wireless communication has also been proposed (see JP-A-2003-214348).
Collection of various data necessary for work management at construction sites have been performed manually, and there has been a problem of inefficiency.
In addition, in a large scale construction site, although the use of work management software allows the resource allocation to be done automatically, significant parts of processes are still required to be done manually thus there has been a problem that it requires a large amount of time for the allocation of resources using the work management software. As a result, an applicable range of the work management software has become very small, so that there has been a problem that it was not fully utilized.
Air compressors used for driving pneumatic tools are often seen at construction sites, but conventionally they don't provide data collection functions, and they have never been used for data collection purposes at construction sites.